INTERSEXUALITY 4ir 



a female one. This was to be expected, since, as Zawadowsky 

 has shown, the plumage is a female one when both the ovary 

 and the testicle are present simultaneously in the body. The 

 experimental bird was as to its external appearance a true 

 lateral intersex. Indeed, it must be supposed that this bird 

 would at the moulting become female on both sides, as in the 

 experiments of Zawadowsky. But on the other hand this 

 experiment gives a good idea how the coincidence of certain 

 abnormal somatic and hormonic conditions may cause inter- 

 sexual types, which at first thought might seem to be without 

 any relation to the hormonic theory. 



In view of the extraordinary variability in intersexuality in 

 the animal kingdom it seems to me inadvisable to set on one 

 side a theory which can explain a great number of facts from 

 a general point of view, because we meet with some facts 

 which cannot be explained by this theory or which seem to 

 contradict it. It is not impossible, as said above, that such a 

 seemingly contradictory fact as, for instance, lateral inter- 

 sexuality, is a special case, which is subject to the general 

 law of the genetic dependence of the sex characters upon 

 sexual hormones influencing the characters of the asexual 

 embryonic tissues, and which at the same time is subject to 

 certain other factors not yet known to us. If we are never to 

 be content with any theory or hypothesis without its explaining 

 everything, it would be impossible to make any step forwards 

 amid the labyrinth of biological facts. 



In the above discussion on intersexuality we have so far 

 omitted a very important question. We spoke of the hormones 

 normally present in every individual as being only of one sex. 

 But it is not absolutely necessary that this should really be so. 

 It is possible that the normal gonad produces simultaneously 

 male and female hormones, but not in similar quantities, one 

 of the two dominating over the other. Such an assumption 

 implies that the normal gonad is bisexual in regard to hormone- 

 production, male and female individuals being different from one 

 another in that the hormones produced by their sex glands differ 

 only quantitatively. One might suppose then that hormonic 

 intersexuality is caused by changes in the quantitative relations 

 between the two hormones (or groups of hormones). There 

 would be normally a "latent intersexuality,'* which becomes 

 manifest when a disturbance in the sex gland takes place. As 



